WASHINGTON — The Food and Drug Administration decided Thursday that consumers can buy devices to jump-start failing hearts at home without a prescription. Some 80 percent of sudden cardiac arrests occur at home.

Before the agency’s decision, consumers who wanted a HeartStart home defibrillator to use in those crucial minutes before an ambulance arrived needed a doctor’s prescription.

The FDA endorsed a July recommendation from its advisory panel to remove the prescription requirement after federal advisers were satisfied that consumers could use the machines safely.

Higher survival rateSudden cardiac arrest differs from a heart attack in that it’s an electrical malfunction of the heart that triggers fatally abnormal heart rhythm. Often, it’s the first hint of heart disease and accounts for roughly 340,000 deaths outside of health care settings each year.

The shock from a defibrillator is the most effective way to end sudden cardiac arrest, which leaves the victim breathing abnormally and unresponsive. HeartStart delivers a jolt of energy equivalent to what it takes to illuminate a 150-watt light bulb for one second.

When the shock is delivered within five minutes of the sudden cardiac arrest, 50 percent of individuals survive, said Deborah DiSanzo, vice president and general manager of cardiac resuscitation at Philips Medical Systems, manufacturer of the device.

Ambulances typically arrive within nine minutes of a 911 call. Ten minutes after the sudden cardiac arrest, the patient has a 1 percent chance of survival, she said.

The division, part of Andover, Mass.-based Philips Electronics North America, said it has sold more than 6,000 devices from November 2002, when the FDA first approved their use, through Sept. 15, 2004.

Waiving prescriptions could raise sales beyond 20,000 per year, a volume high enough to cut a few hundred dollars from the $1,995 price tag, DiSanzo said.

“There are no reports to suggest these devices are unsafe. Furthermore, there is no evidence the prescription requirement increases safety,” Nichol said. “It’s essentially a medical device that is safe for consumers to use.”

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Still, because of the lack of “sufficient scientific data,” the association said it could not endorse or caution against use of the devices in homes.

“Will lives be saved? Lives have already been saved,” Nichol said. But he added that it’s not clear how many “or how many will be in the future.”

Dr. Arthur Kellermann, chairman of the department of emergency medicine at Emory School of Medicine, in Atlanta, said he had “substantial reservations” about the FDA’s actions.

“We have no scientific evidence to support the decision and I don’t think that’s a good way to make health policy,” Kellermann said.

Opponents argue that families with average risk of sudden cardiac arrest could reduce survival chances by wasting precious time looking for a defibrillator gathering dust, rather than calling an ambulance.

Kellermann called the devices “very expensive lottery tickets” since there is “a remote possibility” an individual family may save a life by owning one.